Influence of circular patched EBG substrate on SAR and far-field pattern of dipole phase-array antenna

Interaction between mobile antenna and human head has claimed to introduce serious health hazards, like brain tumor, nerve damage and memory loss. The antenna radiations absorbed in human body are expressed in terms of specific absorption rate (SAR). In this paper influence of circular patched electromagnetic band gap (EBG) substrate on SAR and far-field pattern of dipole phase array antenna to realize low SAR mobile antenna structure is presented. Two element dipole array antenna is used above circular patched EBG substrate, designed at 3.5 GHz frequency which is suitable for fourth generation mobile applications. As a reference model, a conventional rectangular patch EBG substrate is used. The proposed structure has found to reduce SAR in human head by 26 % to 31%. The working of the complete unit is analyzed in CST Microwave Studio® (CST MWS®). Also the effect of phase difference in array element signals on SAR is described.